Taxonomic review of tropical western Atlantic shallow water Drilliidae (Mollusca: Gastropoda: Conoidea) including descriptions of 100 new species
Author
Fallon, Phillip J.
text
Zootaxa
2016
4090
1
1
363
journal article
10.11646/zootaxa.4090.1.1
e6b35f5a-435e-4473-b29e-1e4d842f84b0
1175-5326
263299
203BAC25-B542-48FE-B5AD-EBA8C0285833
Syntomodrillia harasewychi
,
new species
(
Plate 169
)
Drillia lissotropis
auct. non Dall, 1881: is a misidentification, in part, by Dall (1889: 91, R/V
Blake
Sta. 273 [specimens in USNM 87477b only]),
Type
material.
Holotype
8.2 x
2.7 mm
(USNM 1199829); 11
paratypes
: 6 spec., 8.5 x 2.8, 7.9 x 2.8, 8.2 x 2.8, 7.9 x 2.8, 7.0 x 2.6 & 6.8 x
2.5 mm
,
type
locality, M. Harasewych!
May 2012
(USNM 1291371); 5 spec., 7.4 x 2.9, 8.9 x 3.2, 7.1 x 2.6, 7.5 x 2.8 & 7.0 x 3.0 mm, in bottles at
244–274 m
, off Sea Aquarium, Bapor Kibra, Willemstad,
Curaçao
,
Netherlands Antilles
,
12°4'59.51"N
,
68°53'56.61"W
, C. Baldwin!
8 Feb 2013
(USNM 1231399).
Type
locality.
Off Sea Aquarium, Bapor Kibra, Willemstad,
Curaçao
,
Netherlands Antilles
,
12°04'52"N
,
68°53'45"W
, in glass bottles collected at
130–
168 m
.
PLATE 169.
Syntomodrillia harasewychi
.
Upper panel.
Figs. 1–2: holotype off Sea Aquarium, Curaçao, Netherlands Antilles (USNM 1199829). Fig. 1: ventral, lateral, and dorsal views; Fig. 2: enlarged view of protoconch (not to scale).
Lower panel
, paratypes. Figs. 3–10: paratypes, off Sea Aquarium, Curaçao, Netherlands Antilles. Figs. 3, 6–8: USNM 1291371; Figs. 4–5: USNM 1231399; Figs. 9–10: paralectotypes of
Drillia lissotropis
Dall, 1881
from near Barbados that are this species (USNM 87477b).
Other material examined.
Two specimens, 7.5 x 2.8 & 8.3 x 2.7, in 103 fms [
188 m
], R/V
Blake
Sta. 273, near
Barbados
,
paralectotypes
of
Drillia lissotropis
Dall, 1881
, are this species (USNM 87477b).
Range and habitat.
Netherlands Antilles
(
Curaçao
). Taken from
130–
274 m
.
Description.
Shell
very small (to
8.9 mm
in total length), narrowly fusiform; whorls very slightly convex, appearing cinched at the sutures, up to approximately 8¾ whorls, the last approximately 60% of total shell length; surface sculpture of opisthocline ribs. Aperture oval, narrow.
Protoconch
of 2–2½ smooth, translucent whorls, the first partially immersed in the second, which is well rounded.
Axial sculpture
of narrow opisthocline ribs with round crests that run from suture-to-suture on spire whorls, to anterior fasciole on last whorl; ribs on about first 2 teleoconch whorls appear only below periphery, and are almost nodulose; ribs number 10–13 on penultimate and 8–12 on last whorl to varix. Intercostal space varies from less than to at least equal to rib width. Ribs widest on whorl periphery, narrow anteriorly and on shoulder where they are little changed, only slightly recurved.
Varix
larger and wider than preceding ribs, about ⅓-turn from edge of outer lip.
Spiral sculpture
of fine grooves or threads visible between ribs on about the anterior ⅔ of the whorl (absent in sulcal area); threads on anterior fasciole.
Sulcus
absent; former positions of anal sinus represented by recurved ribs and by absence of spiral grooves on whorl shoulders of the last 2 whorls.
Outer lip
thin, outer portion of lip broken on
holotype
and on all
paratypes
, as all are from an octopus midden.
Anal sinus
not complete on specimens examined.
Inner lip
recumbent, but detached, moderately wide, widest along columella, pinched up on anterior portion of columella; formed into a weak callus posteriorly at its junction with the outer lip.
Anterior canal
moderately long, straight except for a slight curve to the right at its end when viewed ventrally; unnotched; columella straight; fasciole not swollen.
Color
uniformly white to off white with a golden brown patch on shoulder and ventral side of the varix.
Remarks.
Taxonomy.
Syntomodrillia harasewychi
is characterized by a narrow glossy shell with a moderately long anterior canal, axial ribs that extend suture-to-suture, spiral grooves or threads in intercostal space, and a varix that is not hump-like positioned about ⅓-turn from the edge of the outer lip. The relatively flat whorls are unique.
Variability.
The average total length of
10 specimens
(two with a missing apex excluded) is
7.86 mm
(7.0–
8.9 mm
) and an average W/
L ratio
of 0.357.
Identification.
Syntomodrillia harasewychi
is very similar to
S. woodringi
Bartsch, 1934
, and similar to
S. portoricana
, new name,
S. hesperia
,
new species
,
S. cookei
(E.A. Smith, 1888)
, and
S. carolinae
Bartsch, 1934
. It has a straighter whorl profile than
S. woodringi
. From
S. portoricana
it differs in the shape of the protoconch, in possessing narrower ribs with round crests, not broad ribs with ridged crests, and is white, not golden brown. From
S
.
hesperia
it differs in the shape of the protoconch, in possessing a less tapered last whorl, an unnotched anterior canal, and is white, not golden brown. From
S. cookei
it differs in being less translucent, in possessing a straighter anterior canal and ribs, and stronger intercostal threads. From
S. carolinae
it differs in having less convex whorls, and in possessing spiral threads or grooves on most whorls, not just the last.
Etymology.
Harasewych’s
Syntomodrillia
, named in honor of Dr. M.G. Harasewych, organizer of the Smithsonian’s Deep Reef Observation Program operating from the
Curaçao
Seaquarium, collector of the first specimens of this species and of several others new to science presented in this work.